*{
    margin: 0;
    padding: 0;
    list-style: none;
}
.btn button{
    margin: 0px 80px;
}
.box .item{
    width: 450px;
    height: 250px;
    flex-shrink: 0;
    text-align: center;
    font-size: 40px;
    font-weight: bolder;
    line-height: 250px;
}
.green{
    background-color: green;
}
.blue{
    background-color: blue;
}
.yellow{
    background-color: yellow;
}
.red{
    background-color: red;
}
.box .boxTop{
    display: flex;
    width: 1800px;
    position: relative;
    left: 0;
    top: 0;
}
.box{
    width: 450px;
    overflow: hidden;
}